The request to support a Molecular Biology and In Situ Hybridization Core stems from the increasing need of multiple projects to access routine molecular biology services. During the past funded period, the Core has served as a centralized repository for reagents and has provided infrastructure and in situ hybridization services. In addition the core has trained several investigators. The aim of the proposed Molecular Biology and In Situ Hybridization Core is to continue to provide these services in a cost-effective manner and to ensure rigorous quality controls. The services offered by the Core are chosen on the basis of broad usage, cost effectiveness, and possibility of improvement upon centralization. A number of time consuming routines are also included as Core services to increase the productivity of the projects. Services that will be provided by the Core are not available from any other facility within this institution. The Core will serve as a centralized unit for technique development and personnel training. New procedures will be established and transferred to the laboratories engaged in the proposed projects. Financial support for the Core will be based on a chargeback system by the five projects. The management of this chargeback system will be provided in conjunction with th Administrative Core of the U54 Center.